Op amps problem Gain Calculation

It helps a bit ...
maybe I should see if Tektronics is still around and try to get a manual.
The real problem is that it's so old --- vacuum tubes instead of integrated
circuits. Thx.
(I'm the OP)

"bj" <hollabaugh@comteck.com> wrote in message
news:61703$4214e673$40b83dbd$2884@ispnews.usenetserver.com...
"THo" <cyberhun@shaw.ca> wrote in message
news:iKqQd.398480$8l.64298@pd7tw1no...
I was given an old oscilloscope, and I'm not sure if it's working
properly.
It's a tube-based one, Tektronic 515. There's only one probe with it,
and
I
connected it to a radio, and it does respond, somewhat. But when there
is
no signal of any kind, the image traced on the screen isn't a moving dot,
it's more like a band, and no matter how it's adjusted the band never
moves
more than halfway across the screen. I've attached a pic of the output
when
there is no input of any kind. How abnormal is this? Is there a way to
re-calibrate it or anything like that?

Tom


No.
This is not normal. It look like a sawtooth waveform from a sweep
circuit.
Sorry, I am not familiar
with this model. Does it have any built-in scope calibrator? Many of
their
even cheap scopes have
a built-in square wave generator. This allows you to set the waveform
amplitude and scope probe
frequency response (capacitance). I realize that this isn't much help.
Why
don't you contact
Tektronics?
Click to expand...
 
On Tue, 15 Feb 2005 17:57:34 +0000, THo wrote:

I was given an old oscilloscope, and I'm not sure if it's working properly.
It's a tube-based one, Tektronic 515. There's only one probe with it, and I
connected it to a radio, and it does respond, somewhat. But when there is
no signal of any kind, the image traced on the screen isn't a moving dot,
it's more like a band, and no matter how it's adjusted the band never moves
more than halfway across the screen. I've attached a pic of the output when
there is no input of any kind. How abnormal is this? Is there a way to
re-calibrate it or anything like that?
Click to expand...
From the picture, this is a seriously ill oscilloscope. )-; alf of the
horizontal amplifier is shot, which you _might_ fix by just replacing a
tube, if you can find one. The vertical amplifier is incredibly noisy,
or set to exceedingly high gain and is picking up crap from the air.

There is a way to recalibrate it, and repair it, but a competent tech
could charge you more than you'd spend on another used unit.

Or, you could keep an eye out on ebay for another of the same model,
and make one working scope from the parts from both.

It is repairable, however, given perseverance, lots of reading, and
another scope. ;-)

Good Luck!
Rich
 
That's what I thought...
Thx

"Rich Grise" <richgrise@example.net> wrote in message
news:pan.2005.02.22.06.34.50.817575@example.net...
On Tue, 15 Feb 2005 17:57:34 +0000, THo wrote:

I was given an old oscilloscope, and I'm not sure if it's working
properly.
It's a tube-based one, Tektronic 515. There's only one probe with it,
and I
connected it to a radio, and it does respond, somewhat. But when there
is
no signal of any kind, the image traced on the screen isn't a moving dot,
it's more like a band, and no matter how it's adjusted the band never
moves
more than halfway across the screen. I've attached a pic of the output
when
there is no input of any kind. How abnormal is this? Is there a way to
re-calibrate it or anything like that?


From the picture, this is a seriously ill oscilloscope. )-; alf of the
horizontal amplifier is shot, which you _might_ fix by just replacing a
tube, if you can find one. The vertical amplifier is incredibly noisy,
or set to exceedingly high gain and is picking up crap from the air.

There is a way to recalibrate it, and repair it, but a competent tech
could charge you more than you'd spend on another used unit.

Or, you could keep an eye out on ebay for another of the same model,
and make one working scope from the parts from both.

It is repairable, however, given perseverance, lots of reading, and
another scope. ;-)

Good Luck!
Rich
Click to expand...
 
John Larkin wrote:

On Fri, 25 Feb 2005 22:00:30 -0600, Chris W <1qazse4@cox.net> wrote:



I am looking for some kind of connector that will let me stack several
of the same PCB on top of each other. Something that will have pins
sticking out the bottom and sockets directly on top so if I had 2 of the
same board they would just plug into each other. Do they make
connectors like that? I have seen socket headers that look like they
would work if only the pins were a little longer. Anyone here know of
somewhere I can buy something like that?



Samtec.


I can't seem to find what I am looking for there. I saw plenty of
Click to expand...
connectors to stack and solder boards. What I am looking for is a
plug/pin combination so I can solder it to each board then plug and
unplug boards on top of each other. In other words, a non permanent
stacking connector. They may have it there but I did a fairly extensive
systematic search of the .100 connectors and didn't see anything.


--
Chris W

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
http://thewishzone.com
 
I am using chips from the ttl logic library and those chips
don't have a pin for Vcc or Gnd in the schematic.
Click to expand...
There is a command (invoke?) for making those pins visible. personally
I think such invisible (implicit) pins are not a good idea.


Wouter van Ooijen

-- ------------------------------------
http://www.voti.nl
Webshop for PICs and other electronics
http://www.voti.nl/hvu
Teacher electronics and informatics
 
On Sat, 05 Feb 2005 09:06:45 -0800, Watson A.Name - "Watt Sun, the Dark
"gmv" <noemail@please.123> wrote in message
"Watson A.Name - "Watt Sun, the Dark Remover"" <NOSPAM@dslextreme.com
"gmv" <noemail@please.123> wrote in message
....
motor caps are too high power for my needs
I am just using small signal here.
NP caps are what i need.

Well, the motor caps are non-polarized. That's what you want.
And they are not electrolytic, I believe, but I'm not certain.
Click to expand...
They are not. They are oil-filled paper. I don't understand the
"too high power", unless you mean simply that they're big fat
things. But they _do_ capacitate!

Aren't there digital filters that you can tailor the response
with smaller caps?

Good Luck!
Rich
 
On Sat, 05 Feb 2005 10:41:43 +0000, gmv wrote:
"Watson A.Name - "Watt Sun, the Dark Remover"" <NOSPAM@dslextreme.com> wrote in message news:11094u4911pj497@corp.supernews.com...
....
Anyway, what you need to do is use a mechanical filter, instead of
trying to make an electronic filter. One thought comes to mind. Use a
speaker and microphone coupled by a mechanical link, and add weight to
that link so that it would only respond to freqs below some low value,
such as 1 Hz. This also makes it a bandpass filter.

That sounds quite a bit more complex to me
then what I am already doing quite successfully.
Click to expand...
Why not add some mass to the geophone itself? Do you have any pictures
of it, or design notes or anything?

Thanks,
Rich
 
JeffM wrote:
Can anyone here help?
Chris W


:You should go through the tutorial.
: Robert Monsen
:
Yup.
http://groups-beta.google.com/group/sci.electronics.design/browse_frm/thread/83cc7b00899e3f85/a7ce2382a41c3c76?q=jeffm_+bolding&_done=%2Fgroups%3Fq%3Djeffm_+bolding%26qt_s%3DSearch+Groups%26&_doneTitle=Back+to+Search&&d#a7ce2382a41c3c76
Click to expand...
Here is a good one:

http://web.mit.edu/eaglecad_v4.09/tutorial-eng.pdf

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.
 
On Wed, 09 Mar 2005 10:20:01 GMT, the renowned Noah Little
<me@privacy.net> wrote:

Michael wrote:
Does anybody know about this:
Smart Tweezers: Automatic RCL meter offered at
http://www.siborg.com/smarttweezers/ST_Canada_2.htm
Does it really do what they claim?

Probably, but when you consider their cost of manufacture compared with
things like made-in China digital fever thermometers and digital
calipers, I think I'll wait a while for the price to come down. Way down.
Click to expand...
Don't hold your breath, those are items that have a relatively large
market and are very simple and undemanding electronically.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
repeat

--
Tater
President of MARS Club (NAR #660)
www.mars-rocketry.com
KC9ESF
NAR #79654 L1
EAA #703312
remove spam spelled backwards to reply


"tater schuld" <taters1@maps.charter.net> wrote in message
news:j%v%d.6004$LI7.2013@fe06.lga...
Hi. I am looking for a simple circuit for LED bargraphs for various
inputs.
supply voltage to be 12v.

I assume if I was just looking for a battery voltage meter that the
easiest
thing would be a batch of zeners, limiting diodes, and the bargraph
display,
but for other types of input i'll need something else, maybe the lm344
solution I've found on the web?

anyone know of a kit of this or maybe (cheap) preassembled modules?
preferably rated for more than 10g?

--
Tater
President of MARS Club (NAR #660)
www.mars-rocketry.com
KC9ESF
NAR #79654 L1
EAA #703312
remove spam spelled backwards to reply
Click to expand...
 
repeat

--
Tater
President of MARS Club (NAR #660)
www.mars-rocketry.com
KC9ESF
NAR #79654 L1
EAA #703312
remove spam spelled backwards to reply


"tater schuld" <taters1@maps.charter.net> wrote in message
news:g2w%d.6005$dy3.2075@fe06.lga...
need some advice, I may need to drop a 12v battery power supply to lower
voltages, like 9 or 6 volts. while a resistor network would do this
easily,
it apears that for high current applications that this would be wastefull.
anyone ever thought of a dc to (lower) dc converter that is a bit more
efficient? cost and weight are a factor so a dc to ac to transformer to dc
wont fly (ack, sorry about the pun)

--
Tater
President of MARS Club (NAR #660)
www.mars-rocketry.com
KC9ESF
NAR #79654 L1
EAA #703312
remove spam spelled backwards to reply
Click to expand...
 
There are a number of regulators available

78XX series, can drop, from memory 30V input down to 12, 9, 8, 5 as
standard, with just a few extra parts, ie, one capacitor.

Paul
 
need some advice, I may need to drop a 12v battery power supply to lower
voltages, like 9 or 6 volts.
Click to expand...
LM317. Add two resistors to get exact voltage you need. Fine for 9V. For
6V, you get get a little more efficiency by using a switching regulator but
at the cost of more complication.

John Musselman
WB6UHF
 
i am familliar with the 78xx series, but i am a bit worried about the heat
output from such devices.

in a spaceraft, the heat will build up. i was wondering if there were some
other options.

--
Tater
President of MARS Club (NAR #660)
www.mars-rocketry.com
KC9ESF
NAR #79654 L1
EAA #703312
remove spam spelled backwards to reply


"loedown" <zero242@internode.on.net> wrote in message
news:424474ef@duster.adelaide.on.net...
There are a number of regulators available

78XX series, can drop, from memory 30V input down to 12, 9, 8, 5 as
standard, with just a few extra parts, ie, one capacitor.

Paul
Click to expand...
 
The regulators come in various sizes, from the small TO92 packages, which
can deliver 100mA, or the TO220 packages which will deliver upto 1A. If the
spaceships are metal, that will provide an ideal heatsink for the TO220
packages. I recently did a job on a JVC DVD player, honestly MR. JVC, who
would put an MPEG decoder IC on the bottom of a drive with about 2 mm of
clearance for air and wonder why the thing has a hissy fit after 40 mins of
playback or so. So not able to heatsink / superglue a heatsink on the top of
the chip, I superglued a small fan onto the mainboard, bolted a 7812 onto
the fan's frame and ran 2 leads back to a +24 V rail, dropped a cap across
the +12 / GND and thing hasn't played up since.

Paul
 
In article <KmC5e.135$yO2.72@lakeread07>, Chris W <1qazse4@cox.net>
wrote:

I have a control box with a 2 wire cable going out to a SPST switch that
switches 120V AC line. I want to put a socket on in the box and a plug
on the wire with the switch so I can disconnect it when it isn't
needed. The easiest thing I can think of would be to use a standard 2
prong outlet and plug. The problem with that is, someone might find the
cable with the switch and plug on the end, wonder what it does, plug it
in and flip the switch. Best case, they trip a breaker, worst case
something starts on fire. So I don't like that idea. I have been
searching Mouser and Digikey and the only other panel mount socket and
matching plug I have found are the round ones that have from two on up
to 100 or maybe more conductors. Even the 2 conductor versions are
around $30 for the plug and socket. I was hoping to spend a lot less
money than that. Any suggestions?
Click to expand...
This power cable, is it like those lamp cords with the inline
power switch? What about a Molex connector?

If I read your post correctly, you do _not_ want to put the
plug end on the cord and the socket side on the box. You
want it the other way around: pins on the load side, sockets
on the hot side.
 
Keyed AC socket and plug? Pins on the plug I'm talking about are...
slightly curved, and laid out in a circular pattern.
Can't remember what they're called. Plug in and twist. Locked!
A bonus is that the socket is so wierd...
Michael
Click to expand...
Same thing I thought of
(because I used one for a switch on a break-it-down-easily system).
http://www.hubbellnet.com/max_htm/tech_stuff/NEMA/ml_2p.htm
 
On Fri, 15 Apr 2005 12:39:08 +0800, "Acceed See"
<invalicd@hotmail.com> wrote:

I have discovered several times after I leave the bus seat and grab the
stainless
steel pole, there was a pak sound. Is that a ESD? Are the charges from my
hand
or the pole?
Click to expand...

A tribo-electric charge is generated when two materials are rubbed
together physically. Electrons are stripped off one material and left
hanging, unattached, on the other. In your case, your pants are
grabbing electrons from the bus seat and you are storing the extra
charge on your body. An ESD event occurs when the extra electrons
balance out by moving to another material that has less electrical
potential. In your case, the metal pole can take on a huge amount of
extra electrons really quickly, so you get a zap. If you were
barefoot, the high electron potential would leak out through your feet
and onto the floor of the bus without any noticable zap.

An ESD event that can be felt is in the 5000+ volt range. ESD events
under 500 volts can instantly destroy CMOS chips and you will never
feel it.

Another myth is that you can't pass a charge unless the object of
less potential is actually grounded or conductive. You can pass a
tribo-electric charge to an insulative material and it will remain
there until that material has a chance to shed the extra baggage to
another unsuspecting low-potential target. The amount of charge passed
can depend on the material and amount of original charge. The only way
to truely eliminate any ESD potential to is to remain connected to an
earth ground via dissipative or conductive material.

More Info:
http://www.all-spec.com/about_esd.html

Glen
All-Spec Industries
 
"as;ldfkj" <filbert@yahoo.com> wrote in message
news:lbpd61974pfavfkei5buvb454j6va4cjtn@4ax.com...
I was wondering if someone can help me out here.

I want to build a circuit that will play ramdom sounds that I can put
onto a chip from my pc.

I want a simple push button control....something like one of those
singing fish but for a different purpose.

I would like to have say 10 or more sound clips that it could play
randomly with the push of a button.
Or if possible and not to complicated multiple buttons for different
clips.

Can someone point me in the right direction here...book, website,
company that sells a kit?
What kind of a chip is normally used to hold the sounds for something
like this...how would I program it?

Looking for a way to do this and keep it small and not really
expensive.
I figure if that make greeting cards that play music and the singing
fish is not that expensive then I should be abe to make something like
this relatively small and cheap.


Thanks for any help!!
Click to expand...

Radio Shack used to sell a voice recorder chip. It was cheap and I think it
will do what you want. They didn't make the chip, so you should still be
able to find it (or something similar).

As I recall, it had an analog input and an analog output, The storage was
on-chip.

Bob
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top